Guided keeper assembly and method for metal forming dies

ABSTRACT

A guided keeper assembly and related method includes a cylindrical base that mounts to a die member using a multi-piece, interlocking flange. The flanges have outer fastener holes and inner arcuate walls that matingly engage a complimentary profile on the outer surface of the base to axially interconnect the same. The flanges also have male and female end connectors which snap lock together around the base in an assembled condition. Mounting screws pass through the fastener holes in the flanges and are anchored in the die member to securely retain the guided keeper assembly in place. A retainer ring is mounted in an associated groove in the base over the heads of the screws to prevent unintentional unfastening of the screws from the die member.

CROSS REFERENCE TO RELATED APPLICATION

The present application is a continuation of and claims priority under35 U.S.C. §120 to commonly assigned, co-pending U.S. application Ser.No. 13/397,912, filed Feb. 16, 2012, entitled GUIDED KEEPER ASSEMBLY ANDMETHOD FOR METAL FORMING DIES, which claims the priority benefit under35 U.S.C. §119, basing said claim of priority on related provisionalpatent U.S. Application No. 61/444,887 filed Feb. 21, 2011, both ofwhich are incorporated hereby by reference.

BACKGROUND OF THE INVENTION

The present invention relates to metal forming dies, and particularly toa guided keeper assembly and associated methods.

Metal forming dies, such as stamping dies and the like are well known inthe art. Progressive metal forming dies are unique, very sophisticatedmechanisms which have multiple stations or progressions that are alignedlongitudinally, and are designed to perform a specified operation ateach station in a predetermined sequence to create a finished metalpart. Progressive stamping dies are capable of forming complex metalparts at very high speeds, so as to minimize manufacturing costs.

Heretofore, the dies used in metal forming presses have typically beenindividually designed, one of a kind assemblies for a particular part,with each of the various components being handcrafted and custom mountedor fitted in an associated die set, which is in turn positioned in astamping press. Not only are the punches and other forming tools in thedie set individually designed and constructed, but the other parts ofthe die set, such as stock lifters, guides, end caps and keepers, camreturns, etc., are also custom designed and individually installed inthe die set. Current die making processes require careful machining,precision holes and recesses in the die set for mounting the individualcomponents, such that the same are quite labor intensive, and requiresubstantial lead time to make, test and set up in a stamping press.Consequently, such metal forming dies are very expensive to design,manufacture and repair or modify.

A modular guided keeper having a base with snap on mounting flangeswhich both precisely aligns the two die members, and positively limitsthe reciprocal travel therebetween would be clearly advantageous insimplifying metal forming die constructions and reducing the costs indesigning, manufacturing and repairing the same. Positive retention ofthe base using snap-on flanges on an associated die member is importantto ensure that the same does not loosen and cause damage to the die setand/or press, which would result in expensive repair and machinedowntime.

SUMMARY OF THE INVENTION

One aspect of the present invention is a metal forming die having firstand second die members mounted a spaced apart distance for reciprocationbetween converged and diverged positions, along with an improved guidedkeeper assembly. The guided keeper assembly includes a base having agenerally cylindrically shaped rigid body with an outside wall portion,first and second oppositely disposed end portions, and a central portionwith a central aperture extending axially therethrough. The base alsohas a retainer ring groove in the outside wall portion, which isdisposed axially between the first and second end portions. The basealso includes a first connector profile on the outside wall portionwhich is disposed axially between the second end portion and the secondretainer ring groove. The guided keeper assembly also includes atwo-piece, interlocking mounting flange which includes a first flangemember having a first mounting portion, at least one first through holedisposed generally perpendicular to the first mounting portion forattaching the first flange member to the first die member, an arcuateinside wall portion with a second connector profile which matinglyengages at least a portion of the first connector profile on the outsidewall portion of the base and axially interconnects the base with thefirst flange member, as well as first and second end connectors. The twopiece interlocking flange also includes a second flange member having asecond mounting portion, at least one second through hole disposedgenerally perpendicular to the second mounting portion for attaching thesecond flange member to the first die member, an arcuate inside wallportion with a third connector profile which matingly engages at least aportion of the first connector profile on the outside wall portion ofthe base and axially interconnects the base and the second flangemember, as well as third and fourth end connectors which securely, yetdetachably, lock with the first and second end connectors on the firstflange member to laterally interconnect the first and second flangemembers with and about the base in an assembled condition to facilitateinstalling the same in the first die member. The guided keeper assemblyalso includes a guide pin having a cylindrically shaped central bodyportion closely received in the central aperture in the base forprecisely guiding reciprocal motion between the first and second diemembers. The guide pin has a first end with an enlarged head shaped toabut the base to positively limit travel between the first and seconddie members, and a second end disposed generally opposite the first end,and having a locator portion that engages the second die member, andprecisely locates the second end of the guide pin on the second diemember. The guided keeper assembly also includes first and secondmounting screws having enlarged head portions with exterior end faces,and threaded shank portions extending through the first and secondthrough holes in the first and second flange members, and beingdetachably anchored in the first die member. The guided keeper assemblyalso includes a retainer ring detachably received and securely retainedin the retainer ring groove in the base, and having an interior facedisposed over at least a portion of the exterior end faces of theenlarged head portions of the first and second mounting screws, wherebyengagement between the exterior end faces of the head portions of thefirst and second mounting screws and the interior face of the retainingring positively prevents the first and second mounting screws fromunintentionally unfastening from the first die member.

Another aspect of the present invention is a guided keeper assembly fora metal forming die having first and second die members mounted a spacedapart distance for reciprocation between converged and divergedpositions. The guided keeper assembly includes a base having a generallycylindrically shaped, rigid body with an outside wall portion, first andsecond oppositely disposed end portions, and a central portion with acentral aperture extending radially therethrough. The base includes aretainer ring groove in the outside wall portion which is disposedaxially between the first and second end portions, as well as a firstconnector profile on the outside wall portion which is disposed axiallybetween the second end portion and the retainer ring groove. The guidedkeeper assembly also includes a two-pieced interlocking mounting flange,which includes a first flange member having a first mounting portion, atleast one of first through holes disposed perpendicularly to the firstmounting portion for attaching the first flange member to the first diemember, an arcuate inside wall portion with a second connector profilewhich matingly engages at least a portion of the first connector profileon the outside wall portion of the base, and axially interconnects thebase with the first flange member, as well as first and second endconnectors. The interlocking mounting flange also includes a secondflange member having a second mounting portion, at least one secondthrough hole disposed generally perpendicular to the second mountingportion for attaching the second flange member to the first die member,an arcuate inside wall portion with a third connector profile whichmatingly engages at least a portion of the first connector profile onthe outside wall portion of the base and axially interconnects the baseand the second flange member, as well as third and fourth end connectorswhich securely, yet detachably lock with the first and second endconnectors on the first flange member to laterally interconnect thefirst and second flange members with and about the base in an assembledcondition to facilitate installing the same in the first die member. Theguided keeper assembly also includes a guide pin having a cylindricallyshaped central portion closely received in the central aperture in thebase for precisely guiding reciprocal motion between the first andsecond die members, along with a first end having an enlarged headshaped to abut the base to positively limit travel between the first andsecond die members, and a second end position generally opposite thefirst end, and having a locator portion that engages the second diemember, and precisely locates the second end of the guide pin on thesecond die member. The guided keeper assembly also includes first andsecond mounting screws having enlarged head portions with exterior endfaces, and threaded shank portions extending through the first andsecond through holes in the first and second flange members, and beingadapted for detachable anchoring in the first die member. The guidedkeeper assembly also includes a retainer ring detachably received andsecurely retained in the retainer ring groove in the base, and having aninterior face disposed over at least a portion of the exterior end facesof the enlarged head portions of the first and second mounting screws,whereby engagement between the exterior end faces of the head portionsof the first and second mounting screws and the interior face of theretaining ring positively prevents the first and second mounting screwsfrom unintentionally unfastening from the die member.

Yet another aspect of the present invention is a method for making ametal forming die having first and second die members mounted a spacedapart distance for reciprocation between converging and divergingpositions using a guided keeper assembly. The method includes forming abase member with a generally cylindrically shaped rigid body with anoutside wall portion, first and second oppositely disposed end portions,and a central portion with a central aperture extending axiallytherethrough. The method also includes forming a retainer ring groove inthe outside wall portion at a location disposed axially between thefirst and second end portions, and forming a first connector profile onthe outside wall portion at a location disposed axially between thesecond end portion and the retaining ring groove. The method alsoincludes forming a two-piece interlocking mounting flange that includesforming a first flange member with a first mounting portion, at leastone first through hole disposed generally perpendicular to the firstmounting portion for attaching the first flange member to the first diemember, an arcuate inside wall portion with a second connector profilewhich is shaped for matingly engaging at least a portion of the firstconnector profile on the outside wall portion of the base, as well asfirst and second end connectors. The mounting flange forming step alsoincludes forming a second flange member, with a second mounting portion,at least one second through hole disposed generally perpendicular to thesecond mounting portion for attaching the second flange member to thefirst die member, an arcuate inside wall portion with a third connectorprofile which is shaped for matingly engaging at least a portion of thefirst connector profile on the outside wall portion of the base, as wellas third and fourth end connectors. The method also includes forming aguide pin with a cylindrically shaped central portion shaped for closereception in the central aperture in the base for precisely guidingreciprocal motion between the first and second die members, a first endwith an enlarged head shaped to abut the base to positively limit travelbetween the first and second die members, and a second end, positionedgenerally opposite the first end, with a locator portion that engagesthe second die member. The method also includes forming a non-threadedbase aperture in the first die member shaped to closely receive thesecond end portion of the base therein, as well as forming first andsecond threaded retainer apertures in the first die member in alaterally spaced apart relationship on opposite sides of the baseaperture. The method further includes providing first and secondmounting screws having enlarged head portions with exterior end faces,and threaded shank portions shaped to extend through the first andsecond through holes in the first and second flange members. The methodalso includes providing a retainer ring shaped for close reception inthe retainer ring groove in the base, and having an exterior face. Themethod further includes positioning the second connector profile on thearcuate inside wall portion of the first flange member abuttinglyagainst an adjacent portion of the first connector profile on the base,and positioning the third connector profile in the arcuate inside wallportion of the second flange member abuttingly against an adjacentportion of the first connector profile on the base at a locationgenerally diametrically opposite the second connector profile on thefirst flange member. The method further includes radially converging thefirst and second flange members about the base until the first, second,third and fourth end connectors snap lock together, thereby axiallyinterconnecting the base with the first and second flange members in anassembled condition to define a base subassembly that facilitatesinstalling the same on the first die member. The method further includespositioning the base subassembly on the first die member with the secondend portion of the base closely received in the base aperture in thefirst die member, and with the first and second through holes in thefirst and second flange members aligned with the first and secondthreaded retainer apertures. The method further includes inserting thethreaded shank portions of the first and second mounting screws throughthe first and second through holes in the first and second flangemembers and into the first and second threaded retainer apertures in thefirst die member and rotating the same to a tightened condition, wherebythe base subassembly is securely, yet detachably connected with thefirst die member. The method further includes inserting the retainingring into the retainer ring groove in the base with the exterior face ofthe retainer ring disposed over at least a portion of the exterior endfaces of the head portions of the first and second mounting screws,whereby engagement between the exterior end faces of the head portionsof the first and second mounting screws and the interior face of theretaining ring positively prevents the first and second mounting screwsfrom unintentionally unfastening from the first die member. The methodfurther includes inserting the central portion of the guide pin into thecentral aperture in the base for precisely guiding reciprocal motionbetween the first and second die members, and connecting the second endof the guide pin with the second die member.

Yet another aspect of the present invention is the guided keeperassembly having a base with snap-on mounting flanges, which incorporatesa very uncomplicated, cost effective design that uses few differentparts and therefore requires less processing and fabrication time andexpense. The base with unique two piece interlocking mounting flange hasa low profile, as well as a small plan footprint which permits use ofthe guided keeper assembly at a wide variety of different locations inany associated die member. The unique base assembly requires only simplemachining to fabricate, yet provides secure retention on a mountingsurface. Preferably, each of the mounting flange pieces which snaptogether about the base have an identical size and shape, and areoperably interchangeable to minimize production and inventory costs.Each of the interlocking flange members can be cut from a single plateof material such as steel or the like by laser cutting or abrasive jetcutting, and snap together easily about the associated base, so thatthere are no loose parts when the base assembly is mounted in anassociated die. Preferably, anti-rotation profiles are provided in theinner ends of the interlocking flange members, which prevent rotationbetween the base and the flange members. The guided keeper base assemblyis simple and requires no special tooling, and is easy to remove andreplace when necessary. The guided keeper assembly and associated basewith interlocking snap-on mounting flanges is efficient in use,economical to manufacture, capable of a long operating life, andparticularly well adapted for the proposed use.

These and other advantages of the invention will be further understoodand appreciated by those skilled in the art by reference to thefollowing written specification, claims, and appended drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a base assembly portion of a guidedkeeper assembly embodying the present invention, shown in an assembledcondition.

FIG. 2 is an exploded perspective view of a guided keeper assemblyembodying the present invention.

FIG. 3 is a plan view of a pair of flange members interconnected forsupporting a base portion of the guided keeper assembly.

FIG. 4 is a vertical cross-sectional view of the base assembly shown inFIG. 1, shown installed in a die member.

FIG. 5 is a perspective view of a base body portion of the guided keeperassembly.

FIG. 6 is a vertical cross-sectional view of the base body.

FIG. 6A is an enlarged fragmentary cross-sectional view of an attachmentgroove portion of the base body.

FIG. 7 is an enlarged fragmentary cross-sectional view of a retainingring groove portion of the base body.

FIG. 8 is a plan view of a retainer ring portion of the guided keeperassembly.

FIG. 9 is a side elevational view of the retainer ring.

FIG. 10 is a longitudinal cross-sectional view of a mounting screwportion of the guided keeper assembly.

FIG. 11 is a perspective view of a base flange member portion of theguided keeper assembly.

FIG. 12 is a perspective view of two base flange members, shownsnap-locked together in an assembled condition.

FIG. 13 is an enlarged fragmentary plan view of an interior edge portionof the base flange with an anti-rotation profile thereon.

FIG. 14 is an enlarged plan view of first and third end connectors onfirst and second flange members, shown in a disassembled condition.

FIG. 14A is an enlarged fragmentary plan view of the first and third endconnectors of FIG. 14, shown snapped together in an assembled condition.

FIG. 15 is an enlarged plan view of second and fourth end connectors onfirst and second flange members, shown in a disassembled condition.

FIG. 15A is an enlarged fragmentary plan view of the second and fourthend connectors of FIG. 14 shown in a snapped together assembledcondition.

FIG. 16 is a perspective view of the base, shown in a partiallyassembled condition.

FIG. 17 is a perspective view of the base, shown in a fully assembledcondition.

FIG. 18 is an exploded perspective view of the base, shown with aportion of a die member to which the base is to be assembled.

FIG. 19 is a perspective view of the base and die member shown in FIG.18, wherein the base body and mounting flange subassembly has beenpositioned in the die member.

FIG. 20 is a perspective view of the base and die member shown in FIGS.18 and 20, wherein four mounting screws have been installed to securely,yet detachably, mount the base on the die member.

FIG. 21 is a perspective view of the base and die member shown in FIGS.18-20, wherein a retainer ring has been placed in the retainer ringgroove in the base body, so as to prevent unintentional unfastening ofthe mounting screws from the die member, and define an assembledcondition.

FIG. 22 is an enlarged top plan view of the fully assembled base and diemember shown in FIG. 21.

FIG. 23 is a perspective view of another embodiment of the presentinvention, shown in an assembled condition.

FIG. 24 is an exploded perspective view of the embodiment illustrated inFIG. 23, shown in a disassembled condition.

FIG. 25 is a perspective view of yet another embodiment of the presentinvention, shown in an assembled condition.

FIG. 26 is an exploded perspective view of the embodiment shown in FIG.25, shown in a disassembled condition.

DETAILED DESCRIPTION

For purposes of description herein, the terms “upper,” “lower,” “right,”“left,” “rear,” “front,” “vertical,” “horizontal” and derivativesthereof shall relate to the invention as oriented in FIGS. 1 and 2.However, it is to be understood that the invention may assume variousalternative orientations and step sequences, except where expresslyspecified to the contrary. It is also to be understood that the specificdevices and processes illustrated in the attached drawings, anddescribed in the following specification, are simply exemplaryembodiments of the inventive concepts defined in the appended claims.Hence, specific dimensions and other physical characteristics relatingto the embodiments disclosed herein are not to be considered aslimiting, unless the claims expressly state otherwise.

The reference numeral 1 (FIG. 2) generally designates a guided keeperassembly that is particularly adapted for use in conjunction with metalforming dies, such as the schematically illustrated metal forming die 2shown in FIG. 2, which has first and second die members 3 and 4,respectively, that are mounted a spaced apart distance for reciprocationbetween converged and diverged positions. The guided keeper assembly 1includes a base assembly 7 having a generally cylindrically shaped,rigid base body 8 with an outside wall portion 9, first and secondoppositely disposed end portions 10 and 11, and a central portion 12with a central aperture 13 extending axially therethrough. Base body 8has a retainer ring groove 14 in the outside wall portion 9 that isdisposed axially between the first and second end portion 10 and 11 ofbase 7. Base body 8 also includes a first connector profile 15 on theoutside wall portion 9 of base body 8 which is disposed axially betweenthe second end portion 11 of base 7 and the retainer ring groove 14.

In the example illustrated in FIGS. 1-4, base assembly 7 also includes atwo piece, interlocking mounting flange assembly 18 (FIG. 3), whichincludes a first flange member 19 having a first mounting portion 20,and at least one first through hole 21 disposed generally perpendicularto the first mounting portion 20 for attaching the first flange member19 to the first die member 3, an arcuate inside portion 22 with a secondconnector profile 23, which matingly engages at least a portion of thefirst connector profile 15 on the outside wall portion 9 of base body 8and axially interconnects base body 8 and the first flange member 19, aswell as first and second end connectors 24 and 25, respectively.

Mounting flange assembly 18 further includes a second flange member,which in the illustrated example, is substantially identical in size andshape to that of the first flange member 19, such that they are operablyinterchangeable to minimize production and inventory costs.Consequently, the similar areas and portions of the first and secondflange members are represented by the same, corresponding referencenumerals, except for the suffix “a” in the numerals of the last. Hence,the second flange member 19 a also has a mounting portion 20 a, at leastone through hole 21 a disposed generally perpendicular to the mountingportion 20 a for attaching the second flange member 19 a to the firstdie member 3, an arcuate inside wall portion 22 a with a connectorprofile 23 a, which matingly engages at least a portion of the firstconnector profile 15, on the outer wall portion 9 of base body 8 andaxially interconnects the base body 8 and the second flange member 19 a,as well as end connectors 24 a and 25 a which securely, yet detachablylock with the first and second end connectors 24 and 25 on the firstflange member 19 to laterally interconnect the first and second flangemembers 19, 19 a, with and about the base body 7 in an assembledcondition, as shown in FIGS. 1 and 4, to facilitate installing the samein the first die member 3.

The guided keeper assembly 1 also includes a guide pin 30 (FIG. 2)having a cylindrically shaped central portion 31 closely received in thecentral aperture 13 in base body 8 for precisely guiding reciprocalmotion between the first and second die members 3, 4. Guide pin 30 alsohas a first end portion 32 with an enlarged head 33 shaped to abut basebody 8 to positively limit travel between the first and second diemembers 3, 4, and a second end portion 34, positioned generally oppositethe first end portion 32, and having a locator portion 35 that engagesthe second die member 4, and precisely locates the second end portion 34of the guide pin 30 on the second die member 4. In the example shown inFIG. 2, the second die member 4 includes a downwardly opening socket 36in which the locator portion of guide pin 30 is closely received. Athreaded retainer screw 67 extends through a non-threaded aperture 68 indie member 4, as well as socket 36, and is anchored in a threadedaperture 69 in the second end 34 of guide pin 3 to securely, yetdetachably, connect the second end 34 of guide pin 30 to the second diemember 4.

The base assembly 7 also includes at least two mounting screws 40 (FIGS.1-4) having enlarged head portions 41 with exterior end faces 42, andthreaded shank portions 43 that extend through the first and secondthrough holes 21, 21 a in the first and second flange members 19, 19 aand are adapted for threaded anchoring in the first die member 3. Thebase assembly 7 also includes a retainer ring 46 that is detachablyreceived and securely retained in the retainer ring groove 14 in base 7,and has an interior face 47 disposed over at least a portion of theexterior end faces 42 of the enlarged head portions 41 of the mountingscrews 40, as shown in FIGS. 1 and 4, whereby engagement between theexterior end faces 42 of the head portions 41 of the mounting screws 40and the interior face 47 of the retaining ring 46 positively preventsthe mounting screws 40 from unintentionally unfastening from the firstdie member 3.

In the examples illustrated herein, the first connector profile 15 onbase body 8 comprises an annularly shaped attachment groove 52 (FIGS.5-7) which is oriented generally perpendicular to the central axis ofbase body aperture 13, opens radially outwardly, and is defined by firstand second radially oriented mutually parallel sidewalls 53 and 54 whichare spaced axially apart a predetermined distance, and an axiallyoriented interior end wall 55 which is disposed generally perpendicularto the first and second sidewalls 53 and 54, and extends axiallytherebetween. The illustrated attachment groove 52 is locatedapproximately midway along the length of base body 8, while theillustrated retainer ring groove 14 is located adjacent to the outer end10 of base body 8.

As best illustrated in FIG. 7, the outwardly most sidewall 37 of theretainer ring groove 14 in base body 8 has a tapered shape whichresiliently urges the interior face 47 of the retainer ring 46abuttingly against the exterior end faces 42 of the head portion 41 ofthe mounting screws 40. As best illustrated in FIG. 7, the outersidewall 37 of retainer ring groove 14 angles away from the outward end10 of base body 8. The innermost sidewall 38 of retainer ring groove 14is flat and oriented generally perpendicular to the central axis of basebody aperture 13, while the end wall 37 is oriented generally paralleltherewith. In the illustrated example, base body 8 has a solid one piececonstruction, and may be lathe machined from a single length of steelbar stock material using inexpensive two-dimensional lathe techniques,instead of expensive live tooling. Also, in the illustrated example, ananti-friction bushing 16 (FIGS. 1-3) is mounted in the central aperture12 of the base body 8 and slidingly receives therein the central portion31 of guide pin 30.

The illustrated retainer ring 46 (FIGS. 8 and 9) has a conventionalsplit, snap ring construction with enlarged ends 43 having throughopenings 49 to receive a tool therein for mounting and unmountingretainer ring 46 in retainer ring groove 14. The interior face 47 ofretainer ring 46 is generally flat and parallel with the exterior face50.

With reference to FIG. 10, the illustrated mounting screws 40 compriseconventional socket head cap screws, wherein the enlarged heads 41 arecylindrical in shape, and include a central socket 45 in the exteriorend faces 42 in which a tool is received to tighten and loosen mountingscrews 40 when retainer ring 46 is removed from base body 8. Theinterior end faces 44 of mounting screws 40 are flat and generallyparallel with the exterior end faces 42.

In the illustrated examples, the first and second flange members 19, 19a comprise side contoured, generally flat plates, which as bestillustrated in FIGS. 11-15A, have a yoke shaped plan profile, withmutually parallel first and second faces 58 & 59, and 58 a & 59 a, andinclude the outer mounting portions 20, 20 a in which the through holes21, 21 a are disposed, and generally U-shaped inner end portions 22, 22a with generally semi-circularly shaped end edges 23, 23 a for closereception in adjacent portions of the attachment groove 52 in base 7,thereby defining the second and third connector profiles.

As noted above, all of the illustrated flange members 19, 19 a areidentical in shape and size, and are preferably made from the same dieor other cutting machine pattern, thereby greatly reducing productionand inventory costs. When assembling any given base assembly 7, one basebody 8 and two flange members 19, 19 a are selected. One of the twoflange members, such as the left flange member 19 in FIG. 12, has itsouter face 58 oriented toward the outer end 10 of base body 9, and itsopposite face 59 oriented toward the inner end 11 of base body 9. Theother of the two flange members, such as the right flange member 19 a inFIG. 12, has its outer face 59 a oriented toward the outer end 10 ofbase body 9, and its opposite face 58 a oriented toward the inner end 11of base body 9. Consequently, flange member 19 is identical in shape andsize to flange member 19 a, with the only difference being that theorientations of the faces 58 & 59 and 58 a & 59 a is reversed to createa pair of flange members 19 and 19 a which snap lock together about basebody 8.

As best illustrated in FIGS. 14-15 a, the first end connector 24 isdisposed on one of the arms of flange member 19 adjacent a firstterminal portion of the inner end portion 22 thereof, and has a firstfinger 63 which protrudes circumferentially outwardly therefrom, with afirst contoured surface 64 that faces in a first radial direction. Thethird end connector 25 a is disposed on a related one of the arms of thesecond flange member 19 a, adjacent a first terminal portion of theinner end portion 22 thereof, and has a second finger 65 a whichprotrudes circumferentially outwardly therefrom, with a third contouredsurface 66 a that mates with the first contoured surface 64 on the firstfinger 63 on the first end connector 24 and faces in a second radialdirection that is radially opposite from the first radial direction,whereby convergence of the first and third end connectors 24, 25 a causethe first and third end connectors 24, 25 a to snap lock together in aself-locking relationship.

Referring again to FIGS. 14-15 a, the second end connector 25 on thefirst flange member 19 is disposed on the other one of the flange arms,opposite the first end connector 24 at a location adjacent to a terminalportion of the inner end portion 22 thereof, and has a finger 65 whichprotrudes circumferentially outwardly therefrom, with a second contouredsurface 66 that faces in a first radial direction. The fourth endconnector 24 a on the other one of the arms of the second flange member19 a is disposed opposite the third end connector 25 a, adjacent aterminal portion of the inner end portion 22 a of the second flangemember 19 a, and has a fourth finger portion 63 a which protrudescircumferentially outwardly therefrom, with a fourth contoured surface64 a that mates with the second contoured surface 66 on the secondfinger 65 of the second end connector 25 and faces in a second radialdirection that is radially opposite from the first direction, wherebyconvergence of the second and fourth end connectors 25, 24 a causes thesecond and fourth end connectors 25, 24 a to snap together in aself-locking relationship. In the example best shown in FIGS. 3 and12-17, the first contoured surface 64 of first finger 63 on the firstend connector member 24 of the first flange member 19 faces radiallyoutwardly, while the third contoured surface 66 a on the third finger 65a on the third end connector 25 a on the second flange member 19 a facesradially inwardly. Further, in the example best shown in FIGS. 3 and12-17, the second contoured surface 66 on the second finger 65 on thesecond end connector member 25 of the first flange member 19 facesradially inwardly, while the fourth contoured surface 64 a on the fourthfinger 63 a on the fourth end connector 24 a on the second flange member19 a faces radially outwardly.

In the example illustrated in FIGS. 11-17, end connectors 25 and 25 acomprise male shaped end connectors, and end connectors 24 and 24 acomprise female shaped end connectors that are configured to lockinglymate with the male end connectors 25 and 25 a. More specifically, thefemale end connectors 24, 24 a have radially oriented inward sides 70,70 a with a generally arcuate shape that extends along a radius ofcurvature that is substantially equal to the radius of curvature of theinterior end wall 55 of the attachment groove 52 in base body 8. Incontrast, the radially oriented outward sides 64, 64 a of the female endconnectors 24, 24 a extends along a radius of curvature that issubstantially less than the radius of curvature of the inside walls 70,70 a thereby forming radially inwardly extending pockets 71, 71 a at theinterior ends 72, 72 a thereof. Generally rounded tips 73, 73 a extendbetween the inward sides 70, 70 a and the outward sides 64, 64 a of thefemale end connectors 24, 24 a. The male end connectors 25, 25 a haveradially oriented outward sides 74, 74 a which, in the illustratedexample, extend along a radius of curvature that is slightly larger thanthe radius of curvature of the outside wall portion 9 of base body 8.The radially oriented inward sides 66, 66 a of the male end connectors25, 25 a have a generally arcuate shape that extends along a radius ofcurvature that is substantially identical to the radius of curvature ofthe outward sides 64, 64 a of the female end connectors 24, 24 a andnests tightly therein. The male end connectors 25, 25 a also have tips75, 75 a which extend between the inward sides 66, 66 a and outwardsides 74, 74 a and include radially inwardly protruding arcuate edges76, 76 a that are configured similar to the pockets 71, 71 a in thefemale end connectors 24, 24 a and snap lock into the pockets 71, 71 ain the female end connectors 24, 24 a to securely, yet detachably,interconnect the first and second flange members 19 and 19 a.

In summary, all of the illustrated flange members, such as flange member19, are identical in shape and size, with a yoke shaped inner portion 22that has a female end connector 24 on the end of one flange arm, and amating male end connector 25 on the end of the other flange arm. Eachfemale end connector 24 has a radially inwardly positioned finger 63,with larger arcuate radially inwardly facing side 70 that is closelyreceived in the attachment groove 52 of base body 8, and a smallerarcuate radially outwardly facing side 64 that snap locks into a matingportion of a male end connector on the flange arm of an adjacent flangemember, such as surface 66 a on the male end connector 25 on flangemember 19 a. Each male end connector 25 has a radially outwardlypositioned finger 65 that overlies the adjacent female finger 63 in theassembled condition, with a radially inwardly projecting and edge 76that snap locks into a mating pocket 71 in the associated female endconnector 24. Each base assembly 7 has one base body 8 and two flangemembers which are paired together by reversing the orientation of one ofthe flange members 19 a relative to the other flange member 19, suchthat the male and female end connectors 24, 25 on one flange member 19align with the female and male end connectors 25 a and 24 a,respectively, on the other flange member 19 a.

Preferably, each flange member 7 is cut from a flat plate of metal orthe like, such that all cut side edges are exactly perpendicular to theopposite faces 58 and 59 of the flange plate 57. Laser cutting, abrasivewater jet cutting, or other similar techniques can be used to quickly,easily and accurately form a large quantity of identical flange members19 from one or more sheets of rigid material, including steel, and thelike.

Referring again to FIGS. 11-17, the end edges 23, 23 a on the first andsecond flange members 19, 19 a include a plurality of axially extending,anti-rotation profiles 80 that abuttingly engage at least one of theinterior end wall 55 and/or sidewalls 53, 54 of the retainer ring groove52, and prevent rotation between the base body 8 and the first andsecond flange members 19, 19 a. In the illustrated example, each of theanti-rotation profiles in the form of notches in the end edges 23, 23 aof the first and second flange members 19, 19 a having a generallyV-shaped plan configuration, which extend radially outwardly to the baseof the V-shape. The V-shaped anti-rotation notches are preferably spacedapart circumferentially along the semi-circular interior end edges 62,62 a of flange members 19, 19 a.

With reference to FIGS. 1-2, each of the illustrated first and secondflange members 19, 19 a includes two through holes 21, 21 a located inthe mounting portions 20, 20 a of the flange members 19, 19 a. Each pairof through holes 21, 21 a is positioned in a laterally spaced apart andaligned relationship and is configured to receive therethrough one ofthe mounting screws 40.

In general, base assembly 7 and associated guided keeper assembly 1 areused to support reciprocating parts of a metal forming die. Morespecifically, as will be readily appreciated by those skilled in theart, base assembly 7, and associated guided keeper assembly 1 aredesigned to mount a wide variety of different sized and shaped die partsin numerous locations and orientations in any given metal forming die,such as die shoes, die pads, pressure pads, stripper pads, etc. Hence,the term “die member” as used herein, refers to any portion of a metalforming die or die set including, but not limited to, an upper die shoe,a lower die shoe 3, and all other die components. With reference toFIGS. 16-22, the illustrated base assembly 7 is mounted in an associateddie member 3 in the following manner. Initially, an unthreaded bore hole90 (FIG. 18) is formed in the mounting surface 91 of die member 3 at thedesired location, and in a shape to closely receive the inner end 11 ofbase body 8 therein. Four threaded retainer apertures 92 are also formedin the mounting surface 91 of die member 3, parallel with bore hole 90,in a generally rectangular pattern centered about the axial center lineof bore 90, and are shaped to receive the shank ends 43 of mountingscrews 40 therein. A pair of flange members 19, 19 a (FIGS. 16 and 17)is positioned on opposite sides of base body 8 a at a location generallyaligned with attachment groove 52, as shown in FIGS. 2 and 16, and thenconverged until the arcuate end edges 23, 23 a and end connectors 24, 24a, 25, 25 a are received within the attachment groove 52 and snap lockedtogether, so as to securely, yet detachably, retain the base body 8 andthe two flange members 19, 19 a together as a unitary base subassembly28, as best shown in FIG. 17, which facilitates mounting the same in diemember 3. Next, the base body 8 with attached flange members 19, 19 adefining base subassembly 28 is then placed on the mounting surface 91of die member 3, with the inward end 11 of base body 8 inserted securelywithin the bore 90 in die member 3, as shown in FIG. 19. The throughapertures 21, 21 a in the flange members 19, 19 a are then centered overthe threaded retainer apertures 92 in die member 3. Mounting screws 40are then inserted through the through holes 21, 21 a in flange members19, 19 a and anchored in the retainer apertures 92 in die member 3,until the same are tight, as shown in FIG. 20. Retainer ring 46 is thensnapped into the retainer ring groove 14 in base body 8, as shown inFIGS. 20-22, whereby engagement between the exterior end faces 42 of thehead portions 41 of the mounting screws 40 and the interior face 47 ofretainer ring 46 positively prevents the mounting screws 40 fromunintentionally unfastening from the die member 3.

The reference numeral 7 c generally designates an alternate baseassembly embodying the present invention, that is specifically designedfor more light duty applications, and has a dual mounting screwfastening system. Since base assembly 7 c is similar to the previouslydescribed base assembly 7, similar parts appearing in FIGS. 1-22 and23-24, respectively, are represented by the same, correspondingreference numeral, except for the suffix “c” in the numerals of thelatter. In base assembly 7 c, each flange member 19 c, 19 ac has onlythrough hole 21 c, 21 ac in the mounting portion 20 c, 20 ac thereof,and accommodates only one mounting screw 40 c therethrough, such thatbase assembly 7 c is attached to an associated die member using only twomounting screws 40 c. Otherwise, base assembly 7 c is substantiallysimilar to the previously described base assembly 7.

The reference numeral 7 d generally designates yet another alternativebase assembly embodying the present invention, that is specificallydesigned for more heavy duty applications, and has four snap-togetherflange members and eight mounting screws. Since base assembly 7 d issimilar to the previously described base assembly 7, similar partsappearing in FIGS. 1-22 and 25-26, respectively, are represented by thesame, corresponding reference numerals, except for the suffix “d” in thenumerals of the latter. In base assembly 7 d, the attachment groove 52 don the base body 8 d is axially enlarged, so as to receive therein twovertical stacks of flange members 19 d, 19 ad, on either side of thebase body 8 d, which provide additional rigidity to the base body 8 dwhen it is attached to an associated die member. Each of the illustratedflange members 19 d, 19 ad includes four circumferentially spaced apartthrough holes 21 d, 21 ad in which four mounting screws 40 d arereceived and served to anchor base assembly 7 d in an associated diemember. Retainer ring 46 d is shaped to cover at least a portion of eachof the outer end faces 42 d on mounting screw heads 41 d, and therebypositively prevent the mounting screws 40 d from unintentionallyunfastening from the associated die member. Otherwise, base assembly 7 dis substantially similar to the previously described base assembly 7.

Each of the base assemblies 7, 7 c and 7 d, along with the associatedguided keeper assemblies, include a base body with snap-on mountingflanges, which provides a very uncomplicated, cost effective design thatuses few different parts, and therefore requires less processing andfabrication. The base assemblies 7, 7 c and 7 d each have a low profile,as well as a small plan footprint which permits use of the same in awide variety of different locations on an associated die member. Each ofthe mounting flange pieces have a substantially identical size andshape, and easily snap together about an associated base so that thereare no loose parts when the base assembly is mounted on an associateddie member. The base assemblies 7, 7 c and 7 d require no specialtooling, and can be easily removed and replaced when necessary.

In the foregoing description, it will be readily appreciated by thoseskilled in the art that modifications may be made to the inventionwithout departing from the concepts disclosed herein. Such modificationsare to be considered as included in the following claims, unless theseclaims by their language expressly state otherwise.

1. In a metal forming die having first and second die members mounted aspaced apart distance for reciprocation between converged and divergedpositions, the improvement of a guided keeper assembly, comprising: abase having: a generally cylindrically shaped, body with an outside wallportion, first and second oppositely disposed end portions, and acentral portion with a central aperture extending axially therethrough;a retainer ring groove in said outside wall portion and disposed axiallybetween said first and second end portions; and a mounting flange grooveon said outside wall portion; a two-piece, interlocking mounting flange,including: a first flange member having a width that is substantiallythe same as the width of said mounting flange groove, at least onethrough hole for attaching said first flange member to said first diemember, a mounting flange groove profile which matingly engages half ofsaid mounting flange groove on said outside wall portion of said baseand axially interconnects said base and said first flange member, andfirst and second end connectors; and a second flange member that isidentical to said first flange member having at least one through holefor attaching said second flange member to said first die member, amounting flange groove profile which matingly engages half of saidmounting flange groove on said outside wall portion of said base andaxially interconnects said base and said second flange member, and thirdand fourth end connectors which securely, yet detachably lock with saidfirst and second end connectors on said first flange member to laterallyinterconnect said first and second flange members with and about saidbase in an assembled condition to facilitate installing the same in saidfirst die member, wherein when said first and second flange members areinterconnected, said mounting flange grooves keep said first and secondflange members aligned; a guide pin having: a cylindrically shapedcentral portion closely received in said central aperture in said basefor precisely guiding reciprocal motion between said first and seconddie members; a first end having an enlarged head shaped to abut saidbase to positively limit travel between said first and second diemembers; and a second end, positioned generally opposite said first end,and having a locator portion that engages said second die member, andprecisely locates said second end of said guide pin on said second diemember; fasteners extending through said through holes in said first andsecond flange members and being anchored in said first die member; and aretainer ring detachably received and securely retained in said retainerring groove in said base, and having an interior face disposed over atleast a portion of said fasteners, whereby engagement between saidfasteners and said retainer ring positively prevents said fasteners fromunintentionally unfastening from said first die member.
 2. A metalforming die as set forth in claim 1, wherein: said mounting flangegroove on said base comprises an annular shaped groove which opensradially outwardly and is defined by first and second radially orientedmutually parallel sidewalls spaced axially apart a predetermineddistance, and an axially oriented interior end wall disposed generallyperpendicular to said first and second sidewalls and extending axiallytherebetween.
 3. A metal forming die as set forth in claim 2, wherein:said first flange member comprises a generally flat plate with mutuallyparallel first and second faces, and includes an outer end portion inwhich said through hole is disposed, and a generally U-shaped inner endportion with a generally semi-circularly shaped end edge configured forclose reception in an adjacent portion of said mounting flange groove insaid base and defines said mounting flange groove profile.
 4. A metalforming die as set forth in claim 3, wherein: said second flange membercomprises a generally flat plate with mutually parallel first and secondfaces, and includes an outer end portion in which said through hole isdisposed, and a generally U-shaped inner end portion with a generallysemi-circularly shaped end edge configured for close reception in anadjacent portion of said mounting flange groove in said base and definessaid mounting flange groove profile.
 5. A metal forming die as set forthin claim 4, wherein: said first end connector is disposed adjacent aterminal portion of said inner end portion of said first flange memberand protrudes circumferentially outwardly therefrom, and has a firstfinger with a first contoured surface that faces in a first radialdirection; and said third end connector is disposed adjacent a terminalportion of said inner end portion of said second flange member andprotrudes circumferentially outwardly therefrom, and has a third fingerwith a third contoured surface that mates with said first contouredsurface of said first finger on said first end connector and faces in asecond radial direction that is radially opposite said first radialdirection, whereby convergence of said first and third end connectorscauses said first and third end connectors to snap lock together in aself-locking relationship.
 6. A metal forming die as set forth in claim5, wherein: said second end connector is disposed adjacent a terminalportion of said inner end portion of said first flange member andprotrudes circumferentially outwardly therefrom, and has a second fingerwith a second contoured surface that faces in a first radial direction;and said fourth end connector is disposed adjacent a terminal portion ofsaid inner end portion of said second flange member and protrudescircumferentially outwardly therefrom, and has a fourth finger with afourth contoured surface that mates with said third contoured surface onsaid third finger on said third end connector and faces in a secondradial direction that is radially opposite said first radial direction,whereby convergence of said second and fourth end connectors causes saidsecond and fourth end connectors to snap lock together in a self-lockingrelationship.
 7. A metal forming die as set forth in claim 1, wherein:said fasteners are detachably anchored in said first die member.
 8. Ametal forming die as set forth in claim 1, wherein: said retainer ringcomprises a split snap ring.
 9. A metal forming die as set forth inclaim 1, including: an anti-friction bushing mounted in said centralaperture of said base and slidingly receiving said central portion ofsaid guide pin therein.
 10. A guided keeper assembly for a metal formingdie having first and second die members mounted a spaced apart distancefor reciprocation between converged and diverged positions, comprising:a base having: a generally cylindrically shaped, body with an outsidewall portion, first and second oppositely disposed end portions, and acentral portion with a central aperture extending axially therethrough;a retainer ring groove in said outside wall portion and disposed axiallybetween said first and second end portions; and a mounting flange grooveon said outside wall portion and disposed axially between said secondend portion and said retainer ring groove; a two-piece, interlockingmounting flange, including: a first flange member having a width that issubstantially the same as the width of said mounting flange groove, atleast one through hole for attaching said first flange member to thefirst die member, an arcuate inside wall portion with a profile whichmatingly engages half of said mounting flange groove on said outsidewall portion of said base and axially interconnects said base and saidfirst flange member, and first and second end connectors; and a secondflange member that is identical to said first flange member having atleast one through hole for attaching said second flange member to thefirst die member, an arcuate inside wall portion with a mounting flangegroove profile which matingly engages half of said mounting flangegroove on said outside wall portion of said base and axiallyinterconnects said base and said second flange member, and third andfourth end connectors which securely, yet detachably lock with saidfirst and second end connectors on said first flange member to laterallyinterconnect said first and second flange members with and about saidbase in an assembled condition to facilitate installing the same in thefirst die member, wherein when said first and second flange members areinterconnected, said mounting flange groove keeps said first and secondflange members aligned; a guide pin having: a cylindrically shapedcentral portion closely received in said central aperture in said basefor precisely guiding reciprocal motion between the first and second diemembers; a first end having an enlarged head shaped to abut said base topositively limit travel between the first and second die members; and asecond end, positioned generally opposite said first end, and having alocator portion that engages the second die member, and preciselylocates said second end of said guide pin on the second die member;fasteners extending through said through holes in said first and secondflange members and being adapted for anchoring in the first die member;and a retainer ring detachably received and securely retained in saidretainer ring groove in said base, and having an interior face disposedover at least a portion of said fasteners, whereby engagement betweensaid fasteners and said retainer ring positively prevents said fastenersfrom unintentionally unfastening from the first die member.
 11. A guidedkeeper assembly as set forth in claim 10, wherein: said mounting flangegroove on said base comprises an annular shaped groove which opensradially outwardly and is defined by first and second radially orientedmutually parallel sidewalls spaced axially apart a predetermineddistance, and an axially oriented interior end wall disposed generallyperpendicular to said first and second sidewalls and extending axiallytherebetween.
 12. A guided keeper assembly as set forth in claim 10,wherein: said fasteners are detachably anchored in said first diemember.
 13. A guided keeper assembly as set forth in claim 12, wherein:said first end connector is disposed adjacent a terminal portion of saidinner end portion of said first flange member and protrudescircumferentially outwardly therefrom, and has a first finger having afirst contoured surface that faces in a first radial direction; and saidthird end connector is disposed adjacent a terminal portion of saidinner end portion of said second flange member and protrudescircumferentially outwardly therefrom, and has a third finger having athird contoured surface that mates with said first contoured surface ofsaid first finger on said first end connector and faces in a secondradial direction that is radially opposite said first radial direction,whereby convergence of said first and third end connectors causes saidfirst and third end connectors to snap lock together in a self-lockingrelationship.
 14. A guided keeper assembly as set forth in claim 13,wherein: said second end connector is disposed adjacent a terminalportion of said inner end portion of said first flange member andprotrudes circumferentially outwardly therefrom, and has a second fingerhaving a second contoured surface that faces in a first radialdirection; and said fourth end connector is disposed adjacent a terminalportion of said inner end portion of said second flange member andprotrudes circumferentially outwardly therefrom, and has a fourth fingerhaving a fourth contoured surface that mates with said second contouredsurface of said second finger on said second end connector and faces ina second radial direction that is radially opposite said first radialdirection, whereby convergence of said second and fourth end connectorscauses said second and fourth end connectors to snap lock together in aself-locking relationship.
 15. A guided keeper assembly as set forth inclaim 10, wherein: said retainer ring comprises a split snap ring. 16.In a method for making a metal forming die having first and second diemembers mounted a spaced apart distance for reciprocation betweenconverged and diverged positions, comprising: forming a base with agenerally cylindrically shaped, body with an outside wall portion, firstand second oppositely disposed end portions, and a central portion witha central aperture extending axially therethrough, including: forming aretainer ring groove in the outside wall portion at a location disposedaxially between the first and second end portions; and forming amounting flange groove on the outside wall portion at a locationdisposed axially between the second end portion and the retainer ringgroove; forming a two-piece, interlocking mounting flange, including:forming a first flange member having a width that is substantially thesame as the width of said mounting flange groove, at least one firstthrough hole for attaching the first flange member to the first diemember, an arcuate inside wall portion with a profile which is shapedfor matingly engaging half of the mounting flange groove on the outsidewall portion of the base, and first and second end connectors; andforming a second flange member that is identical to said first flangemember, at least one second through hole for attaching the second flangemember to the first die member, an arcuate inside wall portion with aprofile which is shaped for matingly engaging half of the mountingflange groove profile on said outside wall portion of the base, andthird and fourth end connectors; forming a guide pin with acylindrically shaped central portion shaped for close reception in thecentral aperture in the base for precisely guiding reciprocal motionbetween the first and second die members, a first end with an enlargedhead shaped to abut the base to positively limit travel between thefirst and second die members, and a second end, positioned generallyopposite the first end, with a locator portion that engages the seconddie member; forming a non-threaded base aperture in the first die membershaped to closely receive the second end portion of the base therein;forming retainer apertures in the first die member in a laterally spacedapart relationship on opposite sides of the base aperture; providingfasteners shaped to extend through the through holes in the first andsecond flange members; providing a retainer ring shaped for closereception in the retainer ring groove in the base, and having aninterior face; positioning the first flange member abuttingly against anadjacent portion of half of the mounting flange groove on the base;positioning the second flange abuttingly against an adjacent portion ofhalf of the mounting flange groove on the base at a location generallydiametrically opposite the first flange member; radially converging thefirst and second flange members about the base until the first, second,third and fourth end connectors snap lock together, thereby axiallyinterconnecting the base with the first and second flange members in anassembled condition to define a base subassembly that facilitatesinstalling the same on the first die member; positioning the basesubassembly on the first die member with the second end portion of thebase closely received in the base aperture in the first die member, andwith the through holes in the first and second flange members alignedwith the retainer apertures in the first die member; inserting thefasteners through the through holes in the first and second flangemembers and into the threaded retainer apertures in the first diemember; inserting the retainer ring into the retainer ring groove in thebase with the retainer ring disposed over at least a portion of thefasteners, whereby engagement between the fasteners and the retainerring positively prevents the fasteners from unintentionally unfasteningfrom the first die member; inserting the central portion of the guidepin into the central aperture of the base for precisely guidingreciprocal motion between the first and second die members; andconnecting the second end of the guide pin with the second die member.17. A method as set forth in claim 16, wherein: said mounting flangegroove forming step portion of said base forming step comprises formingan annularly shaped attachment groove in the outside wall portion of thebase which opens radially outwardly and is defined by first and secondradially oriented mutually parallel sidewalls spaced axially apart apredetermined distance, and an axially oriented interior end walldisposed generally perpendicular to said first and second sidewalls andextending axially therebetween.
 18. A method as set forth in claim 17,wherein: said first flange member forming step includes forming thefirst flange member from a generally flat plate with mutually parallelfirst and second faces, an outer end portion in which the first throughhole is disposed, and a generally U-shaped inner end portion with agenerally semi-circularly shaped end edge configured for close receptionin an adjacent portion of the mounting flange groove in the base todefine the mounting flange groove profile.
 19. A method as set forth inclaim 18, wherein: said second flange member forming step comprisesforming the second flange member from a generally flat plate withmutually parallel first and second faces, an outer end portion in whichthe second through hole is disposed, and a generally U-shaped inner endportion with a generally semi-circularly shaped end edge configured forclose reception in an adjacent portion of the mounting flange groove inthe base to define the mounting flange groove profile.
 20. A method asset forth in claim 16, wherein: said retainer ring providing stepincludes providing a split snap ring.